Is it really possible 'no more blood will run' in the nation that became a cauldron of horrors?

Only the reckless would bet heavily on yesterday's peace deal for the Democratic Republic of Congo coming off. Signed at a ceremony in South Africa by the Congolese and Rwandan presidents, the agreement was hailed as the beginning of the end of Africa's Great War.

"No more blood must run," Joseph Kabila, Congo's youthful president declared as he signed. But four years of fighting have been punctuated by a string of such initiatives, nearly all of which have crumbled.

Previous talks, for example, were held in South Africa's Sun City, leading to the observation that only in Congo could talks on the future of the country be held in a casino.

Meanwhile, in between the rounds of hollow handshakes, Africa's Great War has rumbled on. At various times, six foreign armies (seven, if you include a brief appearance by Chad) have trampled the thick forests and sweeping plains. Some have been interested in fighting, most sought profit and plunder. The price is paid by ordinary Congolese. In just four years, 2.5 million have died, mostly from starvation and disease.

But yesterday, there were reasons to believe this time it might, just might, be for real. Across Africa, peace is in the air. Forty years of fighting in Angola has ended; 10 days ago the Sudanese government and rebels pulled a surprise compromise out of the bag that could, even after yesterday's resumption of fighting, lead to peace.

In Congo, there has also been change. Last year, the mystery assassination of Laurent Kabila, an oafish, obstinate drunk, paved the way for his son Joseph, a shy, well-educated man, to take power and make the running for peace.

Early expectations of the 31-year-old leader who rules a country the size of western Europe were disappointed. Human rights abuses in Kinshasa have continued, corruption remains rampant. But Mr Kabila has shown commitment to working with international players to find a way out of war.

Could yesterday's agreement really signal the beginning of the end? The deal is important because it tackles the root cause of the conflict: the leftover business of the Rwandan genocide. Hutu killers led the slaughter of 800,000 people; four years ago the Tutsi-led Rwandan government invaded Congo vowing not to leave until those men were hunted down.

Now President Kabila, a one-time staunch Hutu ally, is promising to make that happen. His government has agreed to flush the Hutu, a mixture of Interahamwe militia and former Rwandan troops, out of their hiding places deep in the Congolese forest, disarm them, and send them home.

Two weeks later, President Kagame, the man who has tried to heal the festering wounds of his country's genocide, will start withdrawing his troops from eastern Congo, under the watchful eye of UN monitors. Within 90 days, they say, the whole process will be done and dusted.

The problem is, nobody believes it will happen like that. Clare Short, the Secretary of State for International Development, said yesterday that Britain would offer to train a new army for Congo, as it had done in Sierra Leone, as its contribution to cementing the peace. The 90-day time-frame was "not unrealistic", she said.

But almost everyone else thinks the timetable is impossibly ambitious, partly because of the logistical nightmare of finding anyone in eastern Congo, partly because the Interahamwe will not take kindly to being disarmed and dispatched back to Rwanda, and an uncertain fate.

The deal also sidesteps a fundamental reality that is the real block to peace. Although the Congo war started as a fight between government and rebels, that war has largely stopped. Instead, the fighting has shifted behind the front line, to the eastern areas, nominally controlled by Rwandan-backed rebels. That forgotten zone – 30 per cent of the country – has become a cauldron of horrors.

The Rwandan-backed Rally for Congolese Democracy (RDC) rebels are pitted against a multitude of enemies, and themselves. Mai Mai fighters, some of whom think witchcraft can help them fight, control swaths of countryside. Splinter groups from the RCD hold a few small areas. And local Congolese, subjected to extraordinary human rights abuses, hold them in high contempt.

The embattled Rwandans have resorted to extreme measures. After a short-lived mutiny by disgruntled RCD soldiers in the north-eastern city of Kisangani last May, lines of corpses were floating down the Congo. The second largest rebel faction, Jean-Pierre Bemba's Movement for the Liberation of Congo (MLC), has allowed hatred between Hema and Lendu tribes in Ituri to become full-scale massacres.

Mr Bemba, a mobile phone entrepreneur turned warlord, has enjoyed the support of Uganda, the other rebel sponsor. Last year, he agreed to come over to the government side, although he has declined to do so yet. A well-fed, eloquent figure, Mr Bemba is extremely popular in his home area of Gbadolite, in the north-west. Elsewhere in Congo he is regarded with suspicion: he comes from a family that become wealthy during the kleptocracy of Mobutu Sese Seko.

If principle has been lacking in this war, money certainly has not. Laurent Kabila attracted emergency aid from Angola and particularly Zimbabwe by promising diamond concessions to senior generals. On the rebel side, mineral concessions were also divvied out, and ruthlessly controlled.

Eighteen months ago, in a forest clearing outside Kisangani, I met a group of ragged diamond miners. They were preparing lunch, a bunch of caterpillars to be boiled for soup. Ugandan soldiers forced them to mine the diamonds free, they said. "If we refused, they whipped or tortured us," Kombozi Owesaka said.

There has been largely illegal exploitation of coltan, a dull, heavy mineral used in mobile phones, spy satellites and Sony PlayStations, and extraction of timber, coffee and gold. Through the east, almost every family has lost at least one member to hunger, disease or violence. Most have lost several. In the isolated province of Katanga, nominally under the control of Rwanda, villagers have been reduced to a semi-naked state, so much so that they are ashamed to come and seek the food they need.

Rape has become a weapon of war, used with shocking brutality. Human Rights Watch says in one case assailants inserted guns into the vaginas of their victims, aged between five and 80, then shot them.

The war has wreaked environmental havoc. For example, uncontrolled coltan mining near Bukavu has caused the near-extinction of a rare gorilla sub-species. To the north, elephants are in danger.

Uganda has pulled out most of its troops, but Rwanda insists it must stay to ensure the Interahamwe does not return to Rwanda to finish off the murderous work of 1994. But diplomats and analysts are sceptical that the problem is as significant as claimed. Some fear Rwanda has hegemonic ambitions, such as the annexation of eastern Congo. President Kabila will have more problems ditching his erstwhile Hutu allies than he pretends.

Nobody expects the Congo war to be over in 90 days. Yesterday's agreement deals with only one crucial aspect of a conflict that has sent tentacles in many directions. Yet signs of good faith from both sides could offer a solution. Greed, cynicism and opportunism have sustained Africa's most complicated war. Only the absence of those evils will help solve it.

Four years of bloody conflict

* An estimated 2.5 million people have died, mostly through starvation and disease.

* The war began in 1998, when rebels backed by Uganda and Rwanda fought the late president Laurent Kabila. Zimbabwe, Namibia and Angola sent him troops.

* The conflict is rooted in the 1994 Rwandan genocide. Hutu militiamen killed one million Tutsis and Hutus.

* The first invasion in 1996 overthrew Zaire's old dictator, Mobutu Sese Seko. The country was renamed after Mobutu was toppled by Laurent Kabila, who was then backed by Rwanda and Uganda.

* Several wars began, between the government and Rwanda, between rebels and the government, and between rival rebel groups backed by foreign powers.

* Congo's rich natural resources ­ including gold, diamonds, coltan and copper ­ have been plundered by militias and foreign powers.